We're pretty fortunate that a roof mounted readily accessible disconnect has not been a sticking point locally. I would argue that the AC disconnect is still the trunk cable connector, which can be not readily accessible. The AC breaker carrying the combined circuit output in the main distribution panel or the fusible disconnect switch if performing a supply side connection would qualify as the readily accessible disconnect. If you install Enphase I'm sure you are familiar with the manufacturer's excellent white paper on this issue.<div>
<br>
</div><div>I hear what you are saying about the temperature concerns, but there are many installations that have far fewer than 17 inverters per string. A typical residential installation can be split into two or three branch circuits (thank you, Andrew, for keeping me accurate on the string/circuit thing!) The temp concern is definitely something to explore further. There is also the thermal interference factor to take into account for multiple breakers that Gary did not mention. The full datasheet is here:</div>
<div><br></div><div><a href="http://www05.abb.com/global/scot/scot209.nsf/veritydisplay/11d7d0032b466358c125712400340107/$file/2CDC002052D0203_UL489.pdf">http://www05.abb.com/global/scot/scot209.nsf/veritydisplay/11d7d0032b466358c125712400340107/$file/2CDC002052D0203_UL489.pdf</a><br>
</div>
<div><br></div><div>As for the "interior rated" breaker comment, typical AC branch circuit breakers (i.e. Sq D QO) are mounted in wet location NEMA 3R boxes all the time on the exterior of a building. I'm not sure I understand this concern. The temperature derating curve is also similar for ABB and QO breakers. QO Datasheet here:</div>
<div><br></div><div><a href="http://static.schneider-electric.us/docs/Circuit%20Protection/Miniature%20Circuit%20Breakers/QO-QOB%20Circuit%20Breakers/0730CT9801R108.pdf">http://static.schneider-electric.us/docs/Circuit%20Protection/Miniature%20Circuit%20Breakers/QO-QOB%20Circuit%20Breakers/0730CT9801R108.pdf</a><br>
<br>I definitely want to be 100% sure the SolaDeck and breakers are appropriately rated before proceeding. Any comments welcomed...<br><br><div><div style="font-size:13px;font-family:Verdana,Arial,Helvetica,sans-serif"><div style="margin:0px 0px 8px">
<p style="margin:0px"><span style="color:rgb(128,128,128)"><strong>Jason Szumlanski</strong><em> </em></span></p>
<p style="margin:0px"><span style="color:rgb(128,128,128)"><em>Fafco Solar</em></span><br></p></div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, Nov 26, 2012 at 6:37 PM, Gary Willett <span dir="ltr"><<a href="mailto:gary@icarussolarservices.com" target="_blank">gary@icarussolarservices.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<div><font size="+1">JASON:<br>
<br>
I talked to Steve Capozzi of SolaDeck and he sent me additional
info about the circuit breakers:<br>
</font>
<blockquote><font size="+1"><u>Manufacturer</u>: ABB<br>
<br>
<u>Terminal Temp Rating</u>: 75C / 167F<br>
<br>
<u>Reference Temperature</u>: 20C / 68F<br>
<br>
<u>Ambient Temp Derating</u>: <br>
</font>
<blockquote><font size="+1">30C/86F = 18.7A<br>
40C/104F = 17.3A<br>
50C/122F = 15.8A<br>
60C/140F = 14.1A<br>
70C/158F = 12.2A<br>
</font></blockquote>
</blockquote>
<font size="+1"> My concern is that we may be attempting to use an
interior rated AC breaker in a roof-deck-mounted NEMA3-R
enclosure. <br>
<br>
In an Enphase application, with the maximum of 17 inverters per
AC Source Circuit, the continuous current will be 0.9A x 17 x
1.25 = 19.1A. This exceeds the 30C/86F trip current of 18.7A. <br>
<br>
The interior temperature of the SolaDeck could very likely
approach the 60C/140F trip current of 14.1A. <br>
<br>
It seems to me that "nuisance trips" could be a high probability
event. <br>
<br>
Does anyone have any field experience using this Soladeck option
for a AC Source Circuit Combiner Box (SCCB)?<br>
<br>
Another issue, at least in some jurisdictions, is the
requirement for a roof-top AC Disconnect. <br>
<br>
The SolaDeck, when used as an AC SCCB, may not meet the NEC
Article 100 requirements in some jurisdictions for "readily
accessible" because a tool is required to open it.<br>
<br>
<font color="#000000"> </font> <font color="#000000"> </font>
<font color="#000000"> </font> <font color="#000000"> </font>
<font color="#000000"> </font> </font><div>
<p style="margin-bottom:0.0001pt;line-height:normal"><font size="+1" color="#000000"><span>Regards<span>,</span><br>
<br>
<br>
Gary Willett, PE<br>
Icarus Engineering LLC</span></font></p>
<font size="+1"> <font color="#000000"> </font> <font color="#000000"><span>Icarus Solar Services LLC</span></font></font>
<div>
<div><br>
<span><u></u><u></u></span>
</div>
</div></div><div><div>
On 11/26/2012 2:21 PM, Jason Szumlanski wrote:<br>
</div></div></div>
<blockquote type="cite"><div><div>I did get some pictures and info from Soladeck. Here
are some links:
<div><br>
</div>
<div>Pics:</div>
<div>
<div><a href="https://docs.google.com/open?id=1BpiL-1SdSNNsj4wPMQrFCLHH7JT2dek_KftSJl06QLqc0yhJ_1t5oij0aEA6" target="_blank">https://docs.google.com/open?id=1BpiL-1SdSNNsj4wPMQrFCLHH7JT2dek_KftSJl06QLqc0yhJ_1t5oij0aEA6</a></div>
<div><a href="https://docs.google.com/open?id=1cVuhZGeQNHL1IvGvNBa7v93oZyGBvjxCv5yq4AmoyJeDAITxvgMqgECR2yTv" target="_blank">https://docs.google.com/open?id=1cVuhZGeQNHL1IvGvNBa7v93oZyGBvjxCv5yq4AmoyJeDAITxvgMqgECR2yTv</a></div>
<div><a href="https://docs.google.com/open?id=1umslTplnFyZG1eNCZE-MMi_OqrSeirFCPRBl9mFNZJ2gQkBjM5LEXnaPKy2l" target="_blank">https://docs.google.com/open?id=1umslTplnFyZG1eNCZE-MMi_OqrSeirFCPRBl9mFNZJ2gQkBjM5LEXnaPKy2l</a></div>
<div>Specs:</div>
<div>
<div><a href="https://docs.google.com/open?id=13KLAuxUHOR9al7-36reDSJJ7IMnqV3ANPnJILPnrj2xcAi0ksRj67ifKIe7R" target="_blank">https://docs.google.com/open?id=13KLAuxUHOR9al7-36reDSJJ7IMnqV3ANPnJILPnrj2xcAi0ksRj67ifKIe7R</a></div>
<div><a href="https://docs.google.com/open?id=1kvPFcDc1vruS3W_aONlXyIHm1T8-qi4vTpTwGGJ7H0eIwuZ-5e6zrM1CcND5" target="_blank">https://docs.google.com/open?id=1kvPFcDc1vruS3W_aONlXyIHm1T8-qi4vTpTwGGJ7H0eIwuZ-5e6zrM1CcND5</a></div>
<div><a href="https://docs.google.com/open?id=1lM8FtYl9HiYohru32UA_Gb1tXZKZ5iw-8tnSu1Un6g4vcklLL-DK1qLPMdsB" target="_blank">https://docs.google.com/open?id=1lM8FtYl9HiYohru32UA_Gb1tXZKZ5iw-8tnSu1Un6g4vcklLL-DK1qLPMdsB</a></div>
</div>
<div><br>
</div>
<div>I was told Soligent can source the combiners for you (and
me).<br>
<br>
<div>
<div style="font-size:13px;font-family:Verdana,Arial,Helvetica,sans-serif">
<div style="margin:0px 0px 8px">
<p style="margin:0px"><span style="color:rgb(128,128,128)"><strong>Jason
Szumlanski</strong><em> </em></span></p>
<p style="margin:0px"><span style="color:rgb(128,128,128)"><em>Fafco Solar</em></span><a href="http://www.wisestamp.com/apps/wordpress?utm_source=extension&utm_medium=email&utm_term=wordpress&utm_campaign=apps" style="font-family:arial,sans-serif;font-size:80%;color:gray;text-decoration:initial" target="_blank"> </a><span style="color:gray;font-family:arial,sans-serif;font-size:80%"> </span></p>
</div>
</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Mon, Nov 26, 2012 at 1:50 PM,
Jason Szumlanski <span dir="ltr"><<a href="mailto:jason@fafcosolar.com" target="_blank">jason@fafcosolar.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">I
just called Soladeck and they are sending me some more
info on availability. I'll pass it along when I get it.
I didn't realize they made an AC roof mounted string
combiner solution. That's a huge help for 2 or 3 string
Enphase installations (they make both combiners).
<div>
<br>
</div>
<div>While on the subject, we recently started using the
Enphase cable couple with Type TC-ER cable to extend
cabling to junction boxes when necessary... No more
wasting trunk cable connectors! I suppose Type TC-ER
could be used all the way to the main distribution
panel, thereby eliminating junctions on the roof, but
I haven't looked into the cost/benefit of that idea.<br>
<div><br>
</div>
<div>
<div>
<div style="font-size:13px;font-family:Verdana,Arial,Helvetica,sans-serif">
<div style="margin:0px 0px 8px">
<p style="margin:0px"><span style="color:rgb(128,128,128)"><strong>Jason
Szumlanski</strong></span></p>
<p style="margin:0px"><span style="color:rgb(128,128,128)"><em>Fafco
Solar</em></span><br>
<br>
</p>
</div>
</div>
</div>
</div>
</div>
</blockquote></div></div></div></div></div></div></blockquote></div></blockquote></div><br></div></div>
<br>